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b=LfMOpKUY0kSkBKh+0v34G7pUSesBtCCe09LObqD9AaUizQ8XxYq5F1hDWE8qOk1Js A6FKdJImxkAT9Lym8c5dYvXt8+w+Zo4wvV91s2HibfZGKDTbsBCyVR0lTMYexbE8+r Tn8jAQEmr6y+PVxsxcCX5tteSX4r5Czf9awjMF4k05p9Cvi5MV7NHv5GROydwdTDsu 7bafKU4zSxWAM3NsIafvT25unEEis1CMWQd7AeTx6Cms0jtwKTyNvGPhiOcUcsnHw4 Wem3mZc2ktdQYCN4JsDucEKpU1in37L17u1bMN4h2KM/mlA5zjqS6RqmhFEDalI95u DSQTzvSYU/Huw== Date: Fri, 5 Jun 2026 19:16:12 +0100 From: Lorenzo Stoakes To: "David Hildenbrand (Arm)" Cc: Nico Pache , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, aarcange@redhat.com, akpm@linux-foundation.org, anshuman.khandual@arm.com, apopple@nvidia.com, baohua@kernel.org, baolin.wang@linux.alibaba.com, byungchul@sk.com, catalin.marinas@arm.com, cl@gentwo.org, corbet@lwn.net, dave.hansen@linux.intel.com, dev.jain@arm.com, gourry@gourry.net, hannes@cmpxchg.org, hughd@google.com, jack@suse.cz, jackmanb@google.com, jannh@google.com, jglisse@google.com, joshua.hahnjy@gmail.com, kas@kernel.org, lance.yang@linux.dev, liam@infradead.org, mathieu.desnoyers@efficios.com, matthew.brost@intel.com, mhiramat@kernel.org, mhocko@suse.com, peterx@redhat.com, pfalcato@suse.de, rakie.kim@sk.com, raquini@redhat.com, rdunlap@infradead.org, richard.weiyang@gmail.com, rientjes@google.com, rostedt@goodmis.org, rppt@kernel.org, ryan.roberts@arm.com, shivankg@amd.com, sunnanyong@huawei.com, surenb@google.com, thomas.hellstrom@linux.intel.com, tiwai@suse.de, usamaarif642@gmail.com, vbabka@suse.cz, vishal.moola@gmail.com, wangkefeng.wang@huawei.com, will@kernel.org, willy@infradead.org, yang@os.amperecomputing.com, ying.huang@linux.alibaba.com, ziy@nvidia.com, zokeefe@google.com, Usama Arif Subject: Re: [PATCH mm-unstable v19 12/14] mm/khugepaged: avoid unnecessary mTHP collapse attempts Message-ID: References: <20260605161422.213817-1-npache@redhat.com> <20260605161422.213817-13-npache@redhat.com> <44b12ede-1e16-47f5-9051-27fa4ea34236@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <44b12ede-1e16-47f5-9051-27fa4ea34236@kernel.org> X-Rspamd-Queue-Id: DA50B160013 X-Rspam-User: X-Stat-Signature: k9wmghiq8z3ke7ejbwumhfqwpd83ctso X-Rspamd-Server: rspam08 X-HE-Tag: 1780683388-852001 X-HE-Meta: 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 J1Ctl9hp h/H1nAZheVlt6+G1ixIxYbbKCEy1GVPuNRi5DX4NG933pMThRhznr8NsWM9K+JQpZtwJuMPQX7+An7yhJgy/wsz6b9/FWoeER5VMhSdwLPDq1ZzOEdacpVfKYzKUdcghI4v4nMNu14y80cEsS6SoAQMRfOXK3+pLvzyV06zvKKwwkoMFyX1/xyGsn08b7msknJ1PmQhiays/08FQJWC2LqShb8c7g1fPcprvZitwS/EhMvbK8TTE3TEVZBhPzcjeRzj+f3Ee2QbK6NbwKmQy2Pv4aP80fGiDHzchiePl6HVPvMhOusx5u9xPVfUX9dE5xR4q+BoTX4eVV/6iQrgtDK+Exeau0dw/223OtWfmltXWNjBC4AflF1+cAKg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Jun 05, 2026 at 07:49:34PM +0200, David Hildenbrand (Arm) wrote: > On 6/5/26 18:14, Nico Pache wrote: > > There are cases where, if an attempted collapse fails, all subsequent > > orders are guaranteed to also fail. Avoid these collapse attempts by > > bailing out early. > > > > Reviewed-by: Lorenzo Stoakes > > Acked-by: Usama Arif > > Acked-by: David Hildenbrand (Arm) > > Signed-off-by: Nico Pache > > --- > > mm/khugepaged.c | 13 +++++++++++++ > > 1 file changed, 13 insertions(+) > > > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > > index 430047316f43..7de92b28dd30 100644 > > --- a/mm/khugepaged.c > > +++ b/mm/khugepaged.c > > @@ -1499,6 +1499,7 @@ static enum scan_result mthp_collapse(struct mm_struct *mm, > > collapse_address = address + offset * PAGE_SIZE; > > ret = collapse_huge_page(mm, collapse_address, referenced, > > unmapped, cc, order); > > + > > Unrelated to this patch, but not the end of the world :) NA....h that's fine ;) > > -- > Cheers, > > David Cheers, Lorenzo